Intel® Embedded Media and Graphics Driver (Intel® EMGD) FAQ

BIOS and firmware

1. What is UEFI?

UEFI stands for Unified Extensible Firmware Interface. UEFI is a replacement for Legacy System BIOS and is flexible, fast, and efficient and has no driver-size constraints. The UEFI pre-boot firmware architecture can either be 32-bit/64-bit/IA64. There is no binary compatibility. Compatibility support module (CSM) is used to boot legacy operating systems and operate with legacy option ROMs.

2. Is video BIOS (VBIOS) the same as the graphics output protocol (GOP) driver?

No. The GOP driver (also known as EFI video driver in some Intel EMGD documentation) is a replacement for legacy video BIOS and enables the use of UEFI pre-boot firmware without compatibility support module (CSM). The Intel EMGD GOP driver can either be fast boot (speed optimized and platform specific) or generic (platform agnostic for selective platforms).

4. How is the VBIOS Option ROM linked to the display adapter in EFI pre-boot firmware?

The VBIOS Option ROM is linked with the PCI vendor-device ID of the VGA device (typically Bus 0, Device 2, Function 0). This information is embedded in the EFI pre-boot firmware at compile time or merged into the image on the host via the firmware vendor merging utility.

5. Which VBIOS is activated when I have an external graphics card such as Matrox and internal graphics such as internal LVDS?

The answer depends upon the EFI pre-boot firmware setting, if available. If the "PCI as primary" option is available and enabled then the VBIOS option ROM from the Matrox card is activated. If "PCI as primary" is not enabled then the Intel® EMGD VBIOS is activated. Note that there can be only one instance of VBIOS in the platform.

6. What are the VBIOS usage scenarios under Windows XP*?

Windows XP* uses the VBIOS via int 10h for displaying the splash screen and any messages until the graphics driver is loaded. Note that during the OS boot process the OS writes to the framebuffer directly, bypassing VBIOS for display purposes. After the graphics driver is loaded, the OS transfers control to VBIOS during full screen DOS mode and during “blue screen” to display the stack information.